Actuating device



8 Y i we .3; 42 w June 30, 1959 B ADAMSON, JR 2,892,258

ACTUATING DEVICE -F'iled July 18. 1957 34a Y A 36u 340 38a r 26 a INVENTOR.

58 6 Bliss Adamson,Jr., E w v BY :xmh n 26 aN/(71M mi ATTORNEY.

United States Patent ACTUATING DEVICE Bliss Adamson, Jr., Bellaire, Tex., assignor, by mesne assignments, to Welex, Inc., a corporation of DelawareA Application July 18, 1957, Serial No. 672,679

4 Claims. (Cl. 253-178) This invention relates to apparatus for releasing and rctracting sensing elements of well bore logging tools.

Though the invention is adaptable for use Vwith any type well logging tool that employs extendable sensing members in contact withV the walls of a well bore, the speciic adaptation herein disclosed is in combination with an electrical caliper of the type disclosed in Patent No. 2,340,987 to Robidoux.

In the art of calipering well bores the variations in bore diameter are determined by the movement of one or more caliper arms which follow thecontours of the well bore wall upon movement of the caliper through said bore. caliper arms maintained in retracted position. The arms must then be released to contact and respond to the diameter variations of such bores. To provide for logs of intermittent sections of a well bore, or repeated logs of a particular section, means to retract and later release the caliper arms is desired.

It is therefore an object of this invention to provide a novel and simple device to repeatedly release and retract the sensing elements of such well logging tools at the option of the operator. y

Other objects and advantages of the present invention will become apparent from the following description, when taken in connection with the accompanying drawing in which: Y

Figure 1 is a sectional view in elevation of a caliper tool embodying the present inventionand showing the component parts in the position which they assume as the caliper tool is being lowered into a well bore;

Figure 2 is a sectional View in elevation of the caliper tool showing the caliper arms releasedand the position of the component parts as the tool calipers a well bore;

Figure 3 is a cross sectional view taken along line 3--3 of Figure l, illustrating a latching mechanism embodied in the invention.

Referring to Figurel ofthe drawing, a caliper tool is there shown as it is being lowered iuto a well bore 12 upon a single conductor cable 14. The cable may be of a known type commonly used in oil fields for electrical logging and which has a steel sheath. A coupling member 16 provides suitable electrical connection betweenthe cable 14 and the various components of the caliper tool 10.

The caliper tool -10 consists ofan upper lhousing 18 with a closure 20, a lower housing 22 with a closure 24, and a plurality of caliper arms 26. As disclosed in the patent to Robidoux above, the caliper actuating rods 28, the caliper spring 30, and the caliper resistor housingV 32 are well known in the art and are shown merely to illustrate their relationship to the present invention.

'Ihe upper housing 18 has three chambers 34a, `34b, and 34e, each of which is adapted to receive a `tiring mechanism 36a, 36h, and 36C, respectively, which include powder loads 38a, 38b, and 38e. Each of the' firing mechanisms 36 is retained within'each 'chamber- 34 by means of a selectively frangible retaining'rneanssuch as The tool is lowered into a well bore with the Y a shearable snap ring (not shown). The ring mechansms 36 are adapted to be selectively red from the surface through the conductor cable 14 and the coupling member 16. Though not shown, each tiring mechanism 36 may be commonly connected to the conductor of cable 14. When so connected, mechanism 36a may be directly connected to cable 14 while mechanisms 361; and 36e are commonly connected through a resistor to said cable.

Three cylinders 48, 42, and 44 are defined within and along the interior axis of the upper housing 18. Initially the cylinders 40, 42, and 44 are at atmospheric pressure, as the chambers 34a, 34b, and 34e are sealed from the intrusion of well bore uids by O-rings 46.

Mounted within the cylinders 40, 42, and 44 of the upper housing 18 and in the lower housing 22 is a piston rod assembly 48 which extends through the closure 24.

The piston rod assembly 48 is composed of the following related elements: a piston 50 which extends into the cylinder 40 and which is acted on by pressures generated therein; and a piston 52 which is moved upwardly by pressures generated in the cylinder 44 and is moved downwardly by the pressures generated in the cylinder 42. Longitudinal travel of the piston rod assembly 48 within the cylinders 44 and 42 is controlled by an upper stop 52a and a lower stop 52b of the piston 52.

As illustrated in Figure 1, the ignition iilament of powder load 38a is integrally grounded and may be tired merely upon application of electrical current thereto. However, the ignition filaments of powder loads 38h and 38a terminate within chambers 42 and 44 respectively and are without electrical continuity. As provided, the upper piston stop 52a arms the circuit of powder load 38h upon piston 52 being in the upper position shown in Figure 1. Powder load 38e is armed by the lower piston stop 52b when the piston assembly 48 is in the lower position shown in Figure 2.

Thus, when the tiring mechanisms 36 are electrically connected as previously described, application of electrical current through cable 14 will first cause ignition of powder load 38a. Then, as illustrated in Figure 2, a second application of electrical current through cable 14 will ignite powder load 38o, since this is the next powder charge having electrical continuity. Return of piston 52 to the position illustrated in Figure 1 then permits the ignition of powder load 38b upon a third application of electrical current through cable 14.

Fastened to the lower end of the piston rod assembly 48 is a retaining member 54 for a spring 56. Slidably mounted around the shaft of the piston rod assembly 48 is a slotted plate 58 upon which ride pins 60 of the cams 26a of the caliper arms 26. The spring 56 is compressed and thereby exerts a pressure on the plate 58, then to the pin 60, thus holding the arms 26 in the retracted position.

In the upper section of the housing 22 a plurality of spring loaded ball type locking devices 62 are provided. The locking devices 62 are adapted to engage a groove 64 in the piston rod assembly 48 and thereby retain the elements in the position shown in Figure 1 of the drawing.

An illustration of the operation and coaction of the elements of the invention is as follows:

The assembled caliper tool 10, as shown -in Figure l of the drawing, is lowered into a well bore. When the caliper tool 10 is in the desired position for the calipering operation, the caliper arms 26 are released from the retracted position shown by means of the tiring mechanism 36a. VFl`he powder load 38a is selectively ignited from the surface by means of an electrical current passed through the conductor cable 14 and the coupling member 16.

The gases generated by the combustion of the powder load 38a enter the chamber 40 and act upon the piston 50, forcing the entire piston rod assembly 48 downward.

The force generated is sutiicient to disengage the balls of the locking devices 62 from the groove 64. The compression on the spring 56 is released, thereby releasing the springforce on the plate 58. The cams 26a are thus free to rotate about their respective pivot pins and the caliper arms 26 are extended into contact with the -Walls ofthe well bore 12 by the action of the caliper springs 39 on the caliper actuating rods 28.

After the powder load 38a is ignited, the component elements of the caliper tool are in the position shown in Figure 2. As shown, the pressures generated in charnber 40 have sheared the previously described frangible retaining means and forced the tiring mechanism 36a from the chamber 34a, permitting entry of well bore iluids into said chamber.

Downward travel of the piston rod assembly 48 is controlled and limited by the lower stop 52h of the piston 52. The pressure of the well bore iiuids entering the cylinder 40 through chamber 34a act upon the piston 50. The well bore fluids also act on the lower portion of the piston rod assembly 48 in the vicinity of the retaining member 54. The piston 50 is thus pressure balanced and the piston rod assembly 48 floats and exerts no forces on the caliper arms 26.

In the event a repeated run of a particular section of well bore is desired and it should become necessary to retract the caliper arms 26 before the tool 10 is moved in the well bore, the powder load 38e, now armed by contact with the lower piston stop 52b as illustrated in Figure 2, is ignited from the surface by passage of a second electrical current through the conductor cable 14 and the coupling member 16. The expanding gases in the cylinder 44 act on the bottom of the piston 52, forcing the piston rod assembly 48 upward and the cornponent parts assume the position shown in Figure 1. The spring retaining member 54 compresses the spring 56 against the plate 58. The pins 60 ride on the plate 5S and the caliper arms 26 are rotatedabout their respective pivot pins, thus moving into the retracted position. As the locking device 62 engages the groove 64, the component parts are held in the positions shown in Figure l.

The firing mechanism 367C is forced from the charnber 34e by the expanding gases in the chamber 44, permitting well bore fluids to enter said chamber. The pressure of such fluids creates a pressure differential across piston 52, aiding latching member 62 to hold the piston rod vassembly 48 in theV upward position.

When it is then desired to resume calipering the well bore after the operation described above has been performed, the caliper arms 26 are released by igniting the powder load 38E), now armed by upper piston stop 52a. The gases generated in this instance act on the top of the piston 52 in the cylinder 42 and force the piston rod assembly 48 downward in the similar manner as described concerning the ignition of the powder load 38a above.

After `expulsion of firing mechanism 36b from chamber 34b, well bore uids also enter cylinder 42, creating equal pressures across piston 52. Piston rod assembly 4S is again pressure balanced and exerts no forces on the caliper arms 26.

It is pointed out that a plurality of the actuating i devices, as herein described, could be mechanically linked .different frequency, for example.

K fAlthoughthe invention has been described in termsof a speciiic embodiment, it should be understood thatthis was by way of illustration only and that the invention is not limiteduthereto. Accordingly,.modifications of .the

invention are contemplated without departing from the 4 spirit ,of the `described linvention or the scope of the appended claims.

I claim:

1. A device adapted for use with a well bore logging tool, comprising, in combination, an upper housing, a lower housing connected to said upper housing, said upper housing defining a pluralityof cylinders in communication with a plurality of firing chambers, a plurality of powder loads in said firing chambers, a plurality of firing mech- .anisms adapted to ignite said powder loads, a piston rod assembly mounted insaid housings, a plurality of pistons mounted on said vpiston rod assembly and disposed in said cylinders of said upper housing, and latching means adapted to hold said piston rod assembly temporarily against initial movement.

2. A device adapted for use with a caliper tool, comprising, in combination, a plurality of caliper arms adapted to move in and out about pivot pins, an upper housing, a lower :housing connected to said upper housing, said upper housing dening a plurality of cylinders in communicationwith a plurality of firing chambers, a plurality of powder loads in said firing chambers, a plurality of tiring mechanisms adapted to selectively ignite said powder loads, a piston rod assembly mounted in said housings in actuating connection with said caliper arms, .a plurality of pistons mounted on said piston rod assembly and .disposed in said cylinders of said upper housing, and releasable latching means adapted to hold said piston rod assembly and said caliper arms in initially 4retracted position, the action being such that as the Ypowder loads areselectively ignited, the caliper arms are reciprocative movement Ybetween a iirst and a second position relative .to said housing, a first piston disposed withinsaid housing and connected to said piston rod, said iirst piston and said housing defining a first chamber, a second piston disposed within said housing and connected to said piston rod, said second piston and said housing defining a second and a third chamber, an electrically ignited first powder load in communication with said first chamber being adapted to exert a pressure upon saidv lirst piston and move said piston rod from said first to said second position upon ignition, an electrically ignited second powder load in communication with said second chamber .being adapted to be armed only upon movement of said piston rod into said second position and to act upon said second piston to force said piston rod to said first position upon ignition, and an electrically ignited third powder load in communication with said third chamber being adapted to be armed only upon movement of said piston rod from said second to said 'lirst vposition and to act upon said second piston to move said piston rod to said second position upon ignition, said powder loads being adapted to provide communication between respective chambers and well iiuids outside said housing upon selective ignition.

4. An apparatus adapted for actuation of a well bore logging tool, comprising, an actuator housing, a piston vrod axially disposed in said housing and adapted for reciprocative movement between a first and a second position relative to said housing, a first piston disposed within said housing and connected to said piston rod, said first piston and said housing defining a first chamber, a second piston disposed within said housing and connected to said piston rod, said second piston and said housing defining a second and a third chamber, a lirst powder load in communication with'said first chamber being adapted to exert, a pressure upon saidv first piston and move said piston rod from said first to said second position upon ignitioma second powder load in communication with said second lchamber being adapted to be armed only upon said piston rod being in said second position and to act upon said second piston to force said piston rod to said first position upon ignition, and a third powder load in communication with said third chamber being adapted to be armed only upon said piston rod being in said iirst position and to act upon said second piston to move said piston rod to said second position upon ignition, said powder loads adapted to provide communication between respective chambers and well fluids outside said housing upon selective ignition.

References Cited in the le of this patent UNITED STATES PATENTS 

